title: Structural and magnetic phase diagram of CeFeAsO(1- x)F(x) and its relation to high-temperature superconductivity.
abstract: Recently, high-transition-temperature (high-Tc) superconductivity was discovered in the iron pnictide RFeAsO(1-x)F(x) (R, rare-earth metal) family of materials. We use neutron scattering to study the structural and magnetic phase transitions in CeFeAsO(1-x)F(x) as the system is tuned from a semimetal to a high-Tc superconductor through fluorine (F) doping, x. In the undoped state, CeFeAsO develops a structural lattice distortion followed by a collinear antiferromagnetic order with decreasing temperature. With increasing fluorine doping, the structural phase transition decreases gradually and vanishes within the superconductivity dome near x=0.10, whereas the antiferromagnetic order is suppressed before the appearance of superconductivity for x>0.06, resulting in an electronic phase diagram remarkably similar to that of the high-Tc copper oxides. Comparison of the structural evolution of CeFeAsO(1-x)F(x) with other Fe-based superconductors suggests that the structural perfection of the Fe-As tetrahedron is important for the high-Tc superconductivity in these Fe pnictides.
authors.affiliation: Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Q
authors.initials: Q
authors.lastname: Huang
authors.forename: Clarina
authors.initials: C
authors.lastname: de la Cruz
authors.forename: Shiliang
authors.initials: S
authors.lastname: Li
authors.forename: J W
authors.initials: JW
authors.lastname: Lynn
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: M A
authors.initials: MA
authors.lastname: Green
authors.forename: G F
authors.initials: GF
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Li
authors.forename: Z
authors.initials: Z
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authors.forename: J L
authors.initials: JL
authors.lastname: Luo
authors.forename: N L
authors.initials: NL
authors.lastname: Wang
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Dai